Automatic temperature control device



Feb 18, 1947- R. R. CURTIS AUTOMATIC TEMPERAT URE CONTROL DEVICE FiledJan. 24, 1944 fis.

Patented Feb. 1.8, 1947 Y j f 2,415,994

DEVIC Russell R. Curtis, Dayton, Ohio, assigner, by

mesne assignments, to Curtis Automotive De vices, Inc., Dayton, Ohio, acorporation oi' Ohio Application January 24,1944, Serial No. 519,428

My invention relates to iluid'temperature control and particularly toan'improved device functioning automatically to mix hot and'cold iluid,

` v such .as water, in proper proportions to maintain any desired outletor service fluid temperature.

An important object of the invention is to provide a device for thepurpose referred to in which flow controlling valve mechanism`apportions the ini'low of cold and hot` fluid into a mixing chambertogether with means automatically controlled by the temperature of theuid mixture and the pressure of one of the fluid inflows for controllingthe inflow valve structure.

A further object is to provide an arrangementl in which settingmechanism for the inflow apportioning valve structure is automatically`controlled trol by the temperature of the fluid mixture.

Still a further object is to provide an arrange-j,

ment in which setting means for the inowapportioning valve structure isconjointly controlled mechanically, as by spring means, andhydraulically by pressure from one of the 4inovvs, and with suchpressure under control of the temperature of the fluid mixture.

'I'he various features of my invention are embodied in the structureshown on the drawing, in which Figure 1 is a longitudinal section of myimproved Adevice showing the valves 'in one position;

Figure 2 is a similar section showing the'valves l in another position;and

Figure 3 is a. section on plane III-III Figure 2. The device showncomprises a substantially tubular body Ill having the two inlet legs IIand 8 Claims. (Cl. 23.6-12) at its outer end being-bifurcated 'toreceive the head 3| to which it is pivoted by 'a pin 35; The t levertransmits the axial movements of the head 3| to the valve stem 26 lforsetting of the valve assembly for control. of the inlet ilows to themixing chamber` -from the inlet bores I3 and I4,

respectively.

Opposite to the guide cup 29, the body I has the longitudinallyextending boss or Aenlargement Upon its inner side the boss 36 has therecess j `by the pressure of one of the inows under con- I2 with inletbores I3 and I4, respectively. The

inlet legs are connectable with piping I5 and I6 for ow'thereto, of uidat different temperay tures. For example, the pipe I5 may supply coldwater to the inlet leg I I and the pipe I6 hot water to the inlet legI2. The outlet end I1 of the device is connectable with piping I3 forservice delivery of the mixed inlet ilows. I

The portion of the device` adjacent to the inlet legs-provides a mixingchamber I9, the opposed Walls of the inlet legs having inlet passages2|) and 2|, respectively, for flow from the inlet bores 'I3 and I4 intothe mixing chamber. At the inner ends of the passages 20 and 2| are thevalve.

seats 22 and 23 for the valves 24 and 25, respectively, these valveshaving a common stem 26. Guidewings 21 and 23, respectively, on thevalves engage in the passageways 26 and 2| to guide the axial movementof this valve assembly for control ofthe passageways.`

Adjacent to the inlet leg I2, the wall of the body I0 is enlarged tosleeve 29 for receiving a stem 30 extending from a head 3|. A lever 32fulcrumed on a shaft 33 is bifurcated at its inner end 26 to be pivotedthereto by provide a guide cup' or to receive the stem' a pin 34, thelever 36 forming a continuation of the `inlet leg II.

31 forming a pressure chamber whose inner side is spanned by a diaphragm38 detachably secured as by screws 39. The middle portion ofthediaphragm is engaged on its inner side by the top 40 of the head 3|. Aspring encircling the guide cup 29 abuts the head 3| and tends to lshiftit outwardly for outward flexing of the diaphragm. A restricted vent'passage X extends ,Y through the head 3| for connecting the chamber 31withthe mixing chamber I9. Extending longitudinally through the -boss 36is a passageway 42 which communicates at its outer end with the inletbore I3 and at its inner -end communicates with .the cross-passage .43

leading to a valve chamber 44 inthe inner end of the boss. The inner endof the cross-passage 43 provides a valve seat, 45 for a needle valve 46which extends outwardly into the valve cham: ber from the mixed chamberi9.4 .An annular ange 41 guidesthe needle valve and a spring `46encircles .the guide ilange and abuts a collar 49 on the v'alve, thespring tending to hold the valve unseated. A flow passageway I5I)connects the valvechamber 44 with the pressure chamber 31.

Extending intoV the outlet ,end I1 of the device is a lug 5| to which abi-metal thermostat strip 62 is secured at its outer end by va screw 63,this bi-metal strip at its inner end engaging the inner end of theneedle valve' 46. Inwardly of the lug 6I a threaded lug54 receives thethreaded stem 65 on a hand wheel 56, the stem having the abutment en d5l engagingthe bi-metal strip so that by turning of the hand wheel 56the bi-metal strip may be adjusted relative to the needle valve forpre-setting for the desired outow iluid temperature.

My improved device is particularly adaptable for receiving and mixingcold and hot water for delivery for service at a desired temperature.With the arrangement shown, the inlet bore I3 receives cold water,usually from a service line, under comparatively constant temperatureandl pressure, while the inlet bore I4 receives hot water from somesource under temperature which may vary. In the arrangement shown, thebimetal strip 52 will curl outwardly at its inner end4 under temperatureincrease to shift the' M from the cold water tions slightly,

the spring 48 to move the needle valve away from its seat. Figure 2shows the condition where there has been a surplus of hot water inflowwhich caused the bi-metal strip to shift the needle valve to its closedposition to shut of! now from the inlet I3 to the pressure chamber 31.Upon cessation oi flow to the pressure chamber, the spring Il shiftedthe head 3i and the diaphragm outwardly, the entrapped water in thepressure chamber 31, during such outward movement of. the diaphragm,owing out through the small vent passageway X into the mixing chamberI9, the resulting movement of the lever 32 having closed the hot waterinlet valve 25 and opened full the cold water inlet valve 24. Underinuence of this cold water flow through the mix- 'ing chamber, thebi-metal strip is deflected away from the needle valve to permit thespring 4B to gradually unseat the valve whereupon now inlet to thepressure chamber 31 will be resumed. Whenthe needle valve first opens,water owing into the pressure chamber will escape through the smallrestricted passageway X into the mixing chamber, but, as the needlevalve is opened further, pressure will build up in the pressure chamberbehind the diaphragm and then water cannot escape fast enough throughthe passageway X, and the pressure on the diaphragm will overcome thepressure of the spring 4| and thev'lever 32 will be rocked for gradualopening of the hot water inlet valve and movement of the cold waterclosing position, the inlet valve assembly thenv assuming its normalservice position shown on Figure 1 to control and apportion the inflowof cold and hot water for the desired mixture temperature for servicedelivery. During normal service operation of the device, the movingparts will be so balanced that a small amount of water is continuouslybeing metered past the needle valve into the pressure chamber 31 wherethe pressure will vary between close limits to "cause the lever andinlet valve assembly to change posimetering alternately a slight excessof cold water and then of hot water but with the temperature of thedelivered outflow within the desired limits as determined by the settingof the bi-metal strip by the hand wheel 56.

Should the cold water pressure vary for any reason, the pressure in thediaphragm chamber 31 under control of the thermostatically controlledneedle valve will cooperate with the spring 4| to move the lever 32 forproper apportionment oi the cold water and hot water inilow to themixing chamber. If the cold water pressure should rise above normal, thelever 32 will be actuated and moved to reduce the inow of cold water andincrease the inflow o! hot water, and if the cold water pressure shouldnormal the lever 32 will move for setting of the inlet valve structurefor increased cold water inflow and reduced hot water inflow.

It will, of course, be understood that various details of constructionmay be varied through a wide range without departing from the principlesof this invention and it is, therefore, not the purpose to limit thepatent granted hereon otherwise' than necessitated by the scope of theappended claims.

I claim:

. 1. A device for the purpose described comprising a mixing chamber, afirst inlet for flow to the mixing chamber of fluid at one temperatureand a second inlet for ilow to the mixing chamber of fluid at dierenttemperature, a valve asinlet valve toward y decrease below` sembly forcontrolling said inlets, setting means for said valve assembly,mechanical means tending to movesaid setting means for setting of saidvalve assembly for increased ilow into the mixing chamber from said rstinlet and decreased flow from said second inlet, fluid pressure operatedmeans for moving said setting means to counteract said mechanical meansfor decreasing the flow from said flrst inlet and increasing the flowfrom said second inlet, said uid pressure operated means being exposedon one side to the pressure in said mixing chamber, a uid passagewayconnecting said first inlet with said fluid pressure means at the otherside thereof, a metering valve interposed in said passageway forcontrolling the flow through said passageway, and means responsive tothe temperature in said mixing chamber for engaging and controlling saidmetering valve to thereby control the pressure exerted by said iluidpressure means on said setting means.

2. A device for the purpose described comprising a mixing chamber, afirst inlet for ilow to said mixing chamber of fluid at one temperatureand a second inlet for ilow to the mixing chamber of fluid at diierenttemperature, a valve assembly for controlling the flow from said inlets,spring means connected with said valve assembly tending to effectsetting thereof for increased ow from said first inlet and decreasedflow from said second inlet into said mixing chamber, a pressure chamberincluding a diaphragm connected with said valve assembly and exposed onone side directly t0 said mixing chamber, a passageway connecting saidfirst inlet with said pressure chamber on the other side of saiddiaphragm, a metering valve interposed in said passageway forcontrolling the 'ilow therethrough,1 and thermostat means subjected tothe temperature of the mixed fluid in said mixing chamber for engagingand controlling said meteringvalve whereby the pressure in said pressurechamber will control the setting of the valve assembly for apportionmentof the inows from said inlets for maintainingat predeterminedtemperature the fluid 45 to be delivered from said mixing chamber.

3. A device for the purpose describedl comprising a mixing chamberhaving a discharge outlet and having an inlet for cold water and anotherinlet for hot water, a valve assembly for control- 50 ling said inletsfor apportionment of hot and cold water ow into the mixing chamber,spring means tending to setsaid valve assembly for increasing cold waterflow and decreasing hot water flow, a uid pressure chamber and a ilowpas- 55 sage therebetween and said cold water inlet, means in saidpressure chamber subjected on one side to the pressure in said mixingchamber and on its other side to the pressure in said passageway formoving said valving assembly for decreasing cold'water flow andincreasing hot water flow, and valve means interposed in said passagewayand automatically directly controlled by the temperature of the outilowmixture for metering the flow through said owpassageway and therebycontrolling the pressure in said pressure chamber for operation of saidvalve assembly for apportionment of cold and hot water flow formaintaining a predetermined temperature of the outflow mixture.

4. A device for the purpose described comprising a mixing chamber havingadischarge outlet and having an inlet for cold water and another inletfor hot water, a valve assembly for controlling said inlets forapportionment of hot and cold water ow into the mixing chamber, spring yiiow means tending to set said valve assembly for cold water ilow anddecreasing hot pressure chamber subjected pressure in said mixingchamber sembly for controlling the ow from said inlets. spring meansconnected with said valve assembly tending to eii'ect setting thereoffor increased now from said iirst inlet and decreased flow from ber asthe flow into said ishes to thereby 'permit said spring means toVfunction. 6. A device for proportioning fluids to produce pressurediiferential on opposite faces of the dianhragm thereby controllingthesetting'of thev valves relative to said ports.

temperature .control device comprising 1. An automatic regulating lfluid4:iii

' therefrom a mixture having a controlled constant a body member 7#'120,112

` the pressure on oneslde of said diaphragm for regulating the positionof said valves.

8. An automatic temperature regulated ilow control device comprising abody member denning a. mixing chamber, api-metallic stripuin saidchamber having a free end movable in response to temperature variationsiin the chamber, a metering pin in said mixing \chamber actuated by saidfree end of the strip, "an adjustable device accessible from outside thebf dy member for limiting the extent of movemenof the free end of thestrip toward the metering ber having a recess in the mi tion thereof, adiaphragm mo l covering said recess and expos chamber, said diaphragmhavin ing chamber pord to fthe mixing a bleeder pastrapped uid fromsaid'recess into the mixing chamber, a first and having a meteringpassageway controlled by said metering pin extending to the recess, asecond supply a port communicating directly chamber, a valve ,RUSSELL R.CURTIS. REFERENCES The following references are of record in the file ofthis patent:

Um'mn s'rATasrA'raN'rs Number Name l l Date 1,506,758 Little Sept. 2,1924 1,824,057 Robertshaw Sept. 22, 1931 1,869,663 Cartier Aug. 2, 19322,308,165 Fields Jan. 12, 1943 2,308,235 Fields Jan. 12, 1943 2,069,040Lodder Jan. 26, 1937 2,200,318 4Yonkers May 14, 1940 FOREIGN PATENTS-Number f Country 413ste French Dec. 3. 1931 'for co-movement, wherebysaid iii-metallic strip\ controls the position? f the metering pintovary said body memted in the bodyV

